As in any downturn in nthe economy and job looses across the organization chart, the question arises as to whether the vacated organization charts "blanks" will ever be filled in again. In many cases the HR function will continue to list empty organization chart positions and list the positions as "frozen" or as "vacant" but frankly once the next business planning cycle comes around the likelihood is that certain of these positions will either be merged or completely dropped from the org chart.
Upturns take too long to occur and last for too short a time for vacany positions and budget allocations to be justified...rightly or wrongly is another question!
The question is really one of considering if certain jobs are always going to be at risk and if so what happens to bothy "existing generation" and "next generation" employees that might be qualified or training to fill these positions?

Office administration staff, trainers, business analysts (planners), etc might all be part of an ever-decreasing element of the work force. What happens to experienced and qualified staff that are "no longer required"?

I believe that it is very difficult to establish a post that previously existed once an upturn occurs, most likely these positions are gone forever.

I see a strategic position( fulltime or contract) for the continued planning of the changing workforce - and how to prepare the staff and the business for these changes.
Is this an HR function or a Business Planning function?

Your comments please!